“LIDAR” refers to a technique for measuring distances of visible surfaces by emitting light and measuring properties of the reflections of the light. The term “LIDAR” is an acronym for “Light Detection and Ranging” and is sometimes referred to as “laser scanning” or “3D scanning.” In some cases, a LIDAR system includes multiple laser emitters and/or multiple light sensors. Alternatively, or in addition, a LIDAR system may physically move one or more lasers and/or sensors to scan over a scene while repeatedly taking measurements of different surface points.
Generally, the light emitter may comprise a laser that directs highly focused light in the direction of an object or surface. The light sensor may comprise a photodetector such as a photomultiplier or avalanche photodiode (APD) that converts light intensity to a corresponding electrical signal. Optical elements such as lenses may be used in the light transmission and reception paths to focus light, depending on the particular nature of the LIDAR system.
A LIDAR system has signal processing components that analyze reflected light signals to determine the distances to surfaces from which the emitted laser light has been reflected. For example, the system may measure the “flight time” of a light signal as it travels from the laser, to the surface, and back to the light sensor. A distance is then calculated based on the flight time and the known speed of light.
LIDAR systems can be used to inform guidance, navigation, and control systems such as may be used in autonomous vehicles. In systems such as this, one or more LIDAR devices are configured to produce a surface map indicating the 3D coordinates of visible surface points surrounding the vehicle. A guidance, navigation, and control system analyzes this data to identify obstacles, to perform obstacle avoidance, and to determine a desired path of travel. Developing and creating LIDAR systems that are both accurate and have the desired resolution for a particular application can be costly and challenging.